In cosmology, fine tuning refers to the precise balance of cosmological constants that allow the observable universe to exist as it does. These constants include the speed of light, the rate of expansion of the universe, the force of gravity, the nuclear strong force, the electromagnetic force, and many other parameters of the observable universe. These constants exist in such a state of precise equilibrium that any variation to their values would have resulted in a drastically different universe. The fine tuning argument states that these values occurring in such a precise state by mere chance is highly improbable, and that there must have been a creator to fine tune these values in order for our universe to exist as it does and for life to exist on Earth.

Contents

Background

The argument of fine tuning is a rather new one. It has only become popular since the mid-1990s with recent observations about the observable universe and cosmological constants. Cosmologists have theorized that even minute variations in the values of these constants would have resulted in a radically different universe or one altogether unsuitable for supporting life as we know it.

Example 1: The rate of expansion of matter after the Big Bang had to occur at precisely the right rate to allow our universe to form as it has. If it had expanded any faster, matter would have dissipated too quickly for stars and solar systems to form. If it had occurred any slower, the universe would have collapsed upon itself shortly after the Big Bang, resulting in what is known as a Big Crunch.

Example 2: The strong nuclear force is the force which binds protons and neutrons together in the nucleus of an atom. Scientists have calculated that variations in the strong force of as little as ±1% would have drastically affected the breakdown of naturally occurring elements in the universe, prohibiting the formation of stars, black holes, and other natural occurring phenomena.

There are studies of numerous other constants with similar results.

Apologetics

Deists cite this remarkable balance of cosmological constants as evidence of a creator, being a far too unlikely set of circumstances to have occurred naturally. This is quickly becoming the argument of choice of creationism proponents like Lee Strobel. Strobel presents this concept as incontrovertible empirical evidence of God in his book The Case for a Creator.

Counter-apologetics

Essentially this argument is just a variation on the argument from design. The key difference here is that it misrepresents actual scientific evidence in such a way to support an unscientific conclusion. A more scientific conclusion would be to state that there is some unknown natural phenomenon to explain this apparent "fine tuning". See below.

Scientists theorize that given the infinite nature of time and space, an infinite number of other unobservable universes could exist parallel to our own, each with infinite variations of constants. This is known as the multiverse theory. Given infinite possibilities, the formation of a universe such as our own is not so inconceivable.

Another flaw with this argument is that it assumes our universe is finely tuned for the sole purpose of supporting life. This is not the case at all. Given the laws of our universe, scientists theorize that our universe is composed of less than 2% baryonic matter, that is matter consisting of protons, neutrons, and electrons. Dark matter is by far the most common form of matter in our universe. Our universe, if anything, is far more suited for the creation of black holes than it is for supporting life. Life on our planet constitutes only an insignificant portion of our universe.

The Earth's total mass is 5.9736×10^24 KG while the estimated total biomass on Earth is around 7×10^13 KG. This means that the percentage of life on Earth is 1.17182269 × 10^-9. That is .00000000117%. The Earth, let alone the universe, is hardly fine tuned for life. Man has created and tested much more finely tuned mediums for simple life in the form of specialized agar solutions that support life/medium ratios far greater than .00000000117%.

In order for the probability argument to be valid, the fundamental constants under consideration have to be independent. That is, one cannot claim that the gravitational constant and the speed of expansion of the universe were individually tuned, since they are clearly related. The electromagnetic force is mediated by massless photons which travel at the speed of light, so therefore the strength of this force is likely related to the speed of light. Similar relationships may yet emerge between other constants.

If there were a creator who "fine tuned" the universe for our existence, who "fine tuned" the universe in order for said creator to exist? The argument of a creator is infinitely paradoxical.

The initial premise of the argument is that in order for life to exist, the universe must have such properties that warrant a designer. However in this line of reasoning, the designer of those properties would exist in a state where none of these properties were true. Therefore any properties deemed to require a designer can't be necessary for existence in the first place, as the designer can exist without them. The argument is self-refuting.

If one starts with the assumption that humanity is an accident, the fine tuning argument makes no sense since if we are an accident, no fine tuning was necessary. For the fine tuning argument to make any sense, one has to start with the assumption that humanity is not an accident, which begs the question of a creator. But since the purpose of the argument is to prove that there is a god who created us, any such assumption renders the argument circular.

Affirming the consequent

The Fine Tuning argument presupposes that the phenomenon of life and it being presumably only possible in a universe with physical constants exactly like the ones in ours is what qualifies this as special or sublime, however, this is based entirely on nothing other than the entities that determine what qualifies this universe as special or sublime are living (humans). This is an affirming the consequent fallacy. It could also bee seen as a confirmation bias fallacy. In a hypothetical universe with different physical constants, there may be an emergent natural phenomenon that is vastly more complex than the emergence of life, the evolution of life, and the ecology of life. This phenomenon, we will label "phenomenon x", would be impossible in our universe because our physical constants may not permit phenomenon x to occur. There is no objective reason why the possibility of life demands a fine tuner more than phenomenon x. There is also no objective reason why any natural phenomenon, no matter the complexity, should demand a fine tuner any more than another. Hypothetically, if it were shown that life of some kind is possible in most possible universes, but the phenomenon of lightning is only possible in this one, then an apologist might assert that because we occupy the only possible universe with lightning, this universe must have been finely tuned.